How to Schedule LinkedIn and Twitter Posts With an API

LinkedIn's and Twitter's own APIs can't schedule a post. Both publish as soon as you call them, so scheduling from code means running your own queue and calling the API at the right moment, or sending the post to a scheduling API that holds it for you. For a handful of your own accounts, use a scheduling API. If posting is the core of your product, compare the per-account APIs before you build.

We make VoiceMoat, which has one of these APIs. We cover it near the end, including where the others are better.

What the networks' own APIs do

LinkedIn. On the Posts API, PUBLISHED is the only state accepted when you create a post. To post for a member you need the w_member_social permission, which comes with the Share on LinkedIn product. Access tokens last 60 days, and refresh tokens are for approved partners, so otherwise the member has to sign in again.

Twitter. The create post endpoint has no time field. Twitter's API is pay per use: $0.015 for a post and $0.20 for a post with a link. Our Twitter API pricing guide has the details.

Route 1: build your own queue

You'll need:

• A sign-in flow for each network, and safe storage for the tokens

• A table of posts, and a job that runs every minute to pick up what's due

• A record of each attempt, written before you send it

• A rule that an unclear answer is never retried, because the post may be live

• Rate limit handling, and an alert when something fails

The fourth point is the expensive one to get wrong. Our guide to why scheduled posts fail or go out twice covers the failure cases.

Building makes sense when posting is your product, or you need something no vendor offers.

Route 2: use a scheduling API

All of this comes from each company's own docs and pricing pages, read on 9 November 2026.

How to choose:

• Buffer suits low volume on many networks. The Free plan gets 1 key and up to 3,000 requests per 30 days. With no webhooks in the docs, you'd ask for each post's status yourself. Files need a public URL.

• Typefully suits people who live on Twitter and LinkedIn. Its API has signed webhooks, a file upload endpoint and a next-free-slot option.

• Zernio suits products with many customers. Posts are unlimited, but Twitter usage is passed on at Twitter's rates, so a post with a link still costs $0.20.

• Ayrshare is priced for companies posting for their own users, at $299 a month for up to 10 profiles.

• Publer limits its API to Business and Enterprise plans.

If you only want to schedule by hand, our scheduler price comparison is the better read. If you want to do it from Claude or ChatGPT, see what an assistant connection should do on both networks.

What to check in any scheduling API

• An idempotency key. If a request times out, you don't know whether it worked. Sending it again with the same key should return the first answer and create nothing new.

• Key permissions. A script that only saves drafts shouldn't be able to post in public.

• A status for "we don't know". A plain sent or failed hides the dangerous case.

• How long failed webhooks are retried. If your server is down for two hours, does the event still arrive?

• The real publish time in the reply. Some tools shift the time you asked for.

How to verify a webhook signature

Anyone who finds your webhook address can send it a fake event, so check each one. Typefully, Zernio, Ayrshare and VoiceMoat all use HMAC-SHA256, though each signs a slightly different string.

1. Read the raw body before you parse the JSON.

2. Recompute the signature with your secret.

3. Compare the two in constant time.

4. Reject old timestamps where the vendor sends one.

5. Store the event id and ignore repeats, because retries resend the same event.

6. Answer with a 2xx quickly, and do the slow work afterwards.

This Node example uses VoiceMoat's format, t=<seconds>,v1=<hex>:

import { createHmac, timingSafeEqual } from "node:crypto";

function isValid(secret, header, rawBody) {
  if (!header) return false;
  const parts = Object.fromEntries(header.split(",").map((p) => p.split("=")));
  if (Math.abs(Date.now() / 1000 - Number(parts.t)) > 300) return false;
  const expected = createHmac("sha256", secret).update(`${parts.t}.${rawBody}`).digest();
  const given = Buffer.from(parts.v1 ?? "", "hex");
  return given.length === expected.length && timingSafeEqual(given, expected);
}

import { createHmac, timingSafeEqual } from "node:crypto";

function isValid(secret, header, rawBody) {
  if (!header) return false;
  const parts = Object.fromEntries(header.split(",").map((p) => p.split("=")));
  if (Math.abs(Date.now() / 1000 - Number(parts.t)) > 300) return false;
  const expected = createHmac("sha256", secret).update(`${parts.t}.${rawBody}`).digest();
  const given = Buffer.from(parts.v1 ?? "", "hex");
  return given.length === expected.length && timingSafeEqual(given, expected);
}

import { createHmac, timingSafeEqual } from "node:crypto";

function isValid(secret, header, rawBody) {
  if (!header) return false;
  const parts = Object.fromEntries(header.split(",").map((p) => p.split("=")));
  if (Math.abs(Date.now() / 1000 - Number(parts.t)) > 300) return false;
  const expected = createHmac("sha256", secret).update(`${parts.t}.${rawBody}`).digest();
  const given = Buffer.from(parts.v1 ?? "", "hex");
  return given.length === expected.length && timingSafeEqual(given, expected);
}

How VoiceMoat's API works

VoiceMoat is an AI social media tool for LinkedIn and Twitter. In Settings, under API and webhooks, you make a key and tick what it can do. Read, drafts and schedule are ticked by default. Publish isn't, because a key with publish posts with no preview.

This schedules a post for your next open slot. The text is invented:

curl https://app.voicemoat.com/api/v1/posts \
  -H "Authorization: Bearer $VOICEMOAT_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: launch-note-1" \
  -d '{"profile":"linkedin","text":"Three hiring mistakes I made twice","schedule":"next_best_slot"}'

curl https://app.voicemoat.com/api/v1/posts \
  -H "Authorization: Bearer $VOICEMOAT_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: launch-note-1" \
  -d '{"profile":"linkedin","text":"Three hiring mistakes I made twice","schedule":"next_best_slot"}'

curl https://app.voicemoat.com/api/v1/posts \
  -H "Authorization: Bearer $VOICEMOAT_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: launch-note-1" \
  -d '{"profile":"linkedin","text":"Three hiring mistakes I made twice","schedule":"next_best_slot"}'

• Timing: an ISO time at least 10 minutes away, or next_best_slot. Queued posts move by up to 7 minutes, and the reply has the real time.

• Retries: the same Idempotency-Key within 24 hours returns the stored answer and nothing runs again.

• Limits: 60 requests a minute per key, and 20 scheduling or posting calls an hour per account, shared with assistants.

• Unclear results: a 202 with needs_you means the network didn't confirm the post. Don't retry it.

• Credits: scheduling and posting use none. audenAI, the brain inside VoiceMoat, can draft from a topic, which does use credits, and you decide what goes out.

Webhooks cover post.published, post.failed, post.needs_you, post.scheduled, review.comment and review.approved. Failed deliveries are retried after 1, 10 and 50 minutes. After 20 failures in a row the webhook pauses and you get an email. url can be null: a post someone marked as posted by hand arrives with marked_by_user.

What it can't do:

• Post anywhere but LinkedIn and Twitter

• Let your customers connect their accounts, because keys only reach your own profiles

• Connect through a Zapier app, as there isn't one. Anything that can send an HTTP request works

• Take file uploads. Media must already be in your VoiceMoat library

• Move a scheduled post. Cancel it and schedule a new draft

• Run from a browser, or publish Twitter Articles

Our webhook retry window is also much shorter than Zernio's or Ayrshare's. Posts over the limit are refused, so check them with the LinkedIn or Twitter character counter.

The full reference needs no account. To try it on your own accounts, the $5 trial includes the API.